Please explain this situation to someone.

A sudden marriage proposal arrived at Viola, a noblewoman from an impoverished aristocratic family, from the prestigious Fisalis Ducal House. A plain young lady and a beautiful duke—nothing seemed to match. However, the duke himself had his own circumstances. With each having their own reasons and aligned interests, they entered into a political marriage. Will their future bring happiness or misfortune? ***This work has been adapted into a book by Arianrose!*** ***Side stories 'Explaining This Situation from Behind the Scenes' and 'The Circumstances Surrounding the Duke and Duchess of Fisalis' have begun!***